In my U.S. Pat. No. 4,185,191, issued Jan. 22, 1980 and assigned to the assignee of the present invention, I describe a system for use in determining range to an object utilizing a plurality of radiation responsive detectors such as charge-coupled devices arranged in pairs behind a plurality of lenslets which receive radiation from a remote object through the primary lens of the system such as the taking lens of a camera.
A number of improvements and modifications to this system may be found in the following copending applications: Ser. No. 16,595, filed Sept. 22, 1980, now U.S. Pat. No. 4,249,073, issued Mar. 2, 1981 by Norman L. Stauffer, Ser. No. 58,964, filed Sept. 26, 1980, now U.S. Pat. No. 4,250,376, issued Feb. 10, 1981 by James D. Joseph, Ser. No. 74,845, filed Oct. 14, 1980, now U.S. Pat. No. 4,254,330, issued Mar. 3, 1981 by Norman L. Stauffer et al, Ser. No. 85,821, filed Oct. 17, 1979 by Norman L. Stauffer, Ser. No. 99,235, filed Sept. 26, 1980, now U.S. Pat. No. 4,250,377, issued Feb. 10, 1981 by Dennis J. Wilwerding, and Ser. No. 168,225, filed July 10, 1980 by Richard Langlais et al and all assigned to the assignee of the present invention.
In one of the above-mentioned improvements, co-pending application Ser. No. 74,845, now U.S. Pat. No. 4,254,330 a system is disclosed which overcomes a problem that occurs when the scene being viewed contains high frequency components. This problem may occur, for example, in viewing a complex subject containing fine detail. More particularly, when high frequency components exist in the scene being viewed, the range finding or auto focus system may be fooled into establishing a focus position other than the proper one or may cause the operation of the system to be unpredictable. This copending patent application overcomes the problem by enhancing the low frequency components of the signal with apparatus which takes the sums of the outputs of groups of detectors in first and second pluralities of detectors so that the individual fluctuations in individual detectors are smoothed. While this system operates satisfactorily to avoid the problem described in high frequency scenes, the solution requires complex electronic components which are more costly and difficult to fabricate than is desired.